1. Field of the Invention
The present invention relates to an observation system, a recording medium, and a control method of observation system.
2. Description of the Related Art
In culturing cells, if observation can be started concurrently with emergence of a cell mass having a plurality of cells gathering therein and the observation can be conducted sequentially in chronological order, it can be a promising technique to support regenerative medicine, for example. Such observation of cells has been conducted, by using a microscope, for example, when replenishment or replacement of culture fluid in a culture container is required during cell culture, and an image has been picked up as necessary.
However, observation of cells using a microscope requires much expense in time and effort. For example, in order to identify a cell mass having emerged in a container, first, the entire container needs to be observed visually or by using a microscope, and then, a growing state of the individual cell mass needs to be observed under magnification by replacing an objective lens, for example. In micro observation, a narrow field of view causes difficulty in searching a target cell mass, and also causes difficulty in adjusting the cell mass to the field of view. When observing cells, it is preferable to conduct time-lapse observation in which a long-term change is observed from a time of emergence of the cell mass to a time of completion of growth thereof for every predetermined time period. Since the cell mass cannot be observed visually or by using a low-magnification microscope, for example, immediately after seeding of the cell, an observation position needs to be searched and set again several days later.
Further, in observation that is conducted at the time of replenishment or replacement of culture fluid in a culture container usually once in one to three days, it is difficult to conduct observation from a time of emergence of a cell mass, and thus a technique capable of observation of a cell mass from the time of emergence thereof is in high demand. Further, in picking up an image of a cell in each of the cases where the entire container is observed and where a part of the interior of the container is observed under magnification, such a problem that heat generated from illumination and a lens driving system, for example, has effects on growth of the cell arises.
With respect to such observation of cells, a device has been proposed that is configured to save time and effort in switching between the observation of the entire container and the micro observation of a part of the interior of the container, and examples can be found in Japanese Laid-Open Patent Publications 2009-198709 and 2005-295818.
However, it is not easy to manually detect an observation target cell mass in the entire container. Thus, it is preferable that a macro observation image obtained by picking up an image of the entire container is subjected to image processing, thereby extracting the observation target cell mass, and magnifying the portion of the cell mass, as necessary, and imaging it.
However, in that case, image processing for detecting the observation target cell mass from the macro observation image is complicated and requires processing time of several minutes depending on the number of pixels of the macro observation image.
Further, a plurality of observation target cell masses are usually detected in a single container. Thus, a work of individually detecting those cell masses through image processing and picking up an image of each of them needs to be carried out repeatedly, which causes prolonged observation time.
Thus, such a technique is desired that enables an increase in efficiency of the work of detecting a observation target cell mass in the container and magnifying and picking up an image of a portion of each cell mass.